feat: Address rule CA1854

src/Avalonia.Diagnostics/Diagnostics/Views/MainWindow.xaml.cs

@@ -237,9 +237,9 @@ namespace Avalonia.Diagnostics.Views
                             else
                             {
                                 //TODO Use Dictionary.Remove(Key, out Value) in netstandard 2.1
-                                if (_frozenPopupStates.ContainsKey(popup))
+                                if (_frozenPopupStates.TryGetValue(popup,out var value))
                                 {
-                                    _frozenPopupStates[popup].Dispose();
+                                    value.Dispose();
                                     _frozenPopupStates.Remove(popup);
                                 }
                             }

src/Avalonia.Remote.Protocol/MetsysBson.cs

@@ -715,7 +715,8 @@ namespace Metsys.Bson
 
         public MagicProperty FindProperty(string name)
         {
-            return _properties.ContainsKey(name) ? _properties[name] : null;
+            _properties.TryGetValue(name, out var property);
+            return property;
         }
 
         public static TypeHelper GetHelperForType(Type type)
@@ -1196,7 +1197,9 @@ namespace Metsys.Bson
                 }
                 object container = null;
                 var property = typeHelper.FindProperty(name);
-                var propertyType = property != null ? property.Type : _typeMap.ContainsKey(storageType) ? _typeMap[storageType] : typeof(object);
+                var propertyType = property?.Type
+                    ?? (_typeMap.TryGetValue(storageType, out var type1) ? type1 : null)
+                    ?? typeof(object);
                 if (property != null && property.Setter == null)
                 {
                     container = property.Getter(instance);
@@ -1588,7 +1591,7 @@ namespace Metsys.Bson.Configuration
             {
                 return property;
             }
-            return map.ContainsKey(property) ? map[property] : property;
+            return map.TryGetValue(property, out var value) ? value : property;
         }
 
         public void AddIgnore<T>(string name)

src/Windows/Avalonia.Win32/TrayIconImpl.cs

@@ -41,9 +41,9 @@ namespace Avalonia.Win32
 
         internal static void ProcWnd(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam)
         {
-            if (msg == (int)CustomWindowsMessage.WM_TRAYMOUSE && s_trayIcons.ContainsKey(wParam.ToInt32()))
+            if (msg == (int)CustomWindowsMessage.WM_TRAYMOUSE && s_trayIcons.TryGetValue(wParam.ToInt32(), out var value))
             {
-                s_trayIcons[wParam.ToInt32()].WndProc(hWnd, msg, wParam, lParam);
+                value.WndProc(hWnd, msg, wParam, lParam);
             }
 
             if (msg == WM_TASKBARCREATED)